Complicated sewing steps are omitted as much as possible for fashioning clothes formed out of a circularly knitted fabric, prepared by knitting in a circular form without sewing at least a part thereof, and the clothes have no seam allowance. As a result, the clothes give a comfortable feel to the wearers, and circularly knitted fabrics prevail in the field of outerwear such as spats and also in the field of underwear such as shorts, briefs and brassiere.
For the purpose of imparting stretchability to fashioning clothes, elastic fibers such as polyurethane fibers are used in combination with conventional non-elastic fibers. Consequently, the silhouette of the wearer's body is known to become beautiful due to the increased stretchability of the knitted fabric. Use of an elastic fiber, in combination, increases the stretchability of the knitted fabric for fashioning clothes, and improves the supporting function such as of a body silhouette to make the knitted fabric adapted to consumers' needs. On the other hand, because the constraining forces across the wearer's body becomes strong, the wearer sometimes has an uncomfortable feel during wear.
Furthermore, when an elastic fiber such as a polyurethane one is used for knitting the fabric, the fabric has a high density and becomes thick, and the size of the body part of the fashioning clothes becomes small. As a result, many courses must be formed, to maintain a necessary size per garment. The amount of the fiber used per garment is therefore increased, and a problem, that a lightweight garment cannot be obtained, occurs.
In order to solve such a problem, attempts to knit a fabric with a sparse stitch have been made when a circularly knitted fabric for fashioning clothes were knitted. However, when an elastic fiber is used in combination, the knitted fabric density does not decrease substantially, even if a sparse stitch is used, due to the shrinkage force of the elastic fiber, and only a thick fabric is obtained.
A conventional widely-used circularly knitted fabric is usually opened, and fed to a dry heat setting machine of a tenter type to decide the fabric size.
In contrast to the above circularly knitted fabric, fashioning clothes are often dyed, without sewing the body part of the clothes, while the fabric is in a circular form. The knitted fabric subsequent to dyeing is then fitted into a metal frame and set to decide the size thereof. When the metal frame size is made significantly large and the knitted fabric is set at high temperature, the knitted fabric becomes relatively thin. However, when this procedure is employed, the following problem arises: the knitted fabric portion that is contacted with the metal frame receives a large amount of heat in comparison with the knitted portion that is not contacted therewith to produce uneven setting. Moreover, because the knitted fabric is contacted with the metal frame, breakage of the polyurethane elastic fiber and yellowing of the non-elastic fiber take place when the setting temperature is made excessively high. Consequently, the setting temperature cannot be made significantly high.
As a result, fashioning clothes for which an elastic fiber is used to increase the stretchability of the knitted fabric become thick and the length thereof becomes short. Moreover, when the numbers of knitted stitches is increased, the amount of the fiber used increases, and the weight per garment increases. In addition to this problem, another problem, that the production efficiency in the heat setting decreases, also arises.
In order to improve the problems, the stretch ratio of the elastic fiber is set at a value as low as possible when knitting is conducted in order that the elastic fiber shows soft stretchability. However, when a bare yarn of the elastic fiber is fed to a knitting machine with fashioning mechanism at a low stretch ratio, the elastic yarn is hardly unwound smoothly from the cheese. As a result, the problems that yarn breakage often takes place on the knitting machine, to lower the production efficiency, and defects are formed in the products, remain. Moreover, when a covering textured yarn in which an elastic fiber, as a core, is covered with a covering yarn such as a polyester or nylon yarn, is used, the following problems arise: poor unwindability, or the like, of the fiber occurs during the covering texturing step; because the elastic fiber has a low traveling tension, it yields to a winding tension caused by the ballooning of the covering yarn, and uneven covering, like corkscrew twisting and uneven drawing, is formed on the covering textured yarn to deteriorate the quality of the knitted fabric.